Soil Compaction Machine with Internal Combustion Engine and Improved Air Supply

ABSTRACT

A hand-guided soil compacting machine, such as a vibration tamper, is provided. The compacting machine includes an internal combustion engine for driving a compacting plate and at least one guide bar for holding and/or guiding the soil compacting machine.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to foreign Patent Application DE 102009 017209.2, filed on Apr. 9, 2009, the disclosure of which isincorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The invention relates to a hand-guided soil compaction machine and,especially, a vibration tamper for soil compaction.

BACKGROUND OF THE INVENTION

One known soil compaction machine includes a superstructure with aninternal combustion engine which drives a compacting plate belonging toa substructure via a crank mechanism or the like, with which soil or thelike can be compacted. A handlebar is arranged on the superstructure,with which a user can keep the tamper in operation and/or can guide thesame.

One known tamper or vibration tamper with a low-vibration guide barincludes a superstructure, or an upper mass, and a substructure, or alower mass. The total mass and especially the mass ratio ofsuperstructure to substructure have a relevant influence on theeffectiveness and the convenience in operation of a soil compactionmachine, and especially a vibration tamper.

SUMMARY OF THE INVENTION

Embodiments of the present invention advantageously reduce the overallmass of a hand-guided soil-compaction machine with an internalcombustion engine.

In accordance with one embodiment of the present the invention, a soilcompaction machine comprises an internal combustion engine for driving acompacting plate and at least one guide bar for holding and/or guidingthe soil compaction machine, with the guide bar comprising a flowchannel through which a supply of the combustion air to the internalcombustion engine occurs at least in sections.

The guide bar thus assumes a conducting function in accordance with theinvention in addition to the mere holding and guiding function, which isthe conduction of the combustion air. This advantageously allows for areduction in weight or mass, especially in the superstructure of thesoil compacting machine. Furthermore, there is a reduction in theoverall size and reduction in individual parts. As a result of newconstructional degrees of freedom, it is further possible to useair-filter types whose use was previously not possible. As a result ofthe spatial spacing of air filter and internal combustion engine whichis bridged by means of the flow channel, the combustion air can be drawnin a region in which the thermal loading and/or the dust exposure islow. Moreover, heating up of the air filter or the air-filter housing byheat conduction and/or heated engine cooling air by the internalcombustion engine can be prevented.

The combustion air is used for the combustion process in the internalcombustion engine. It expressly does not concern the exhaust gases fromthe combustion process. Preferably, the flow of the combustion air iscaused by the intake process of the internal combustion engine.

An advantageous further development of the invention provides that theflow channel is arranged to be integrated in the guide bar. As describedherein, this integrated arrangement (“integrated flow channel”)comprises a defined flow route or flow path which is fixedly connectedwith the guide bar, which flow path is suitable to pass through at leasta part of the combustion air to bridge a distance. Preferably, this flowpath follows the contour of the guide bar at least in sections.

A soil compacting machine in accordance with another aspect of thepresent invention is a tamping device or a vibration tamper with atamping plate or the like which is driven by means of the internalcombustion engine. This aspect of the invention is not exclusivelylimited to such tamping devices, but can advantageously be implementedin all hand-guided soil compacting machines with an internal combustionengine and a guide bar such as a vibration plate for example.

It is provided according to a preferred further development that theguide bar is formed by a hollow section at least in sections whosehollow space forms the integrated flow channel. The guide bar cancomprise for this purpose a metal material and/or a plastic materialand/or a composite material. The term “hollow section” also comprisesmulti-chamber sections within the terms of the invention. The axiallongitudinal extension of the hollow section can be straight and/orspatially curved. In particular, the guide bar is made at least insections of a bent or multi-component tube of a random and especiallycircular cross section.

It is provided according to a preferred further development that furtherfunctional means are arranged on the guide bar, such as especially anair-filter unit which is in flow connection with the integrated flowchannel. Said air-filter unit preferably comprises an air filter and isused for cleaning the combustion air. One fundamental idea of thisfurther development is to provide several additional functions to theguide bar in addition to the further conducting of combustion air.

The realization of the flow connection between an air-filter unit on theguide bar and the integrated flow channel is achieved in an especiallyelegant manner by means of a connecting flange. This connecting flangeis preferably arranged as a separate component and can be L-shaped orT-shaped for example.

In a further advantageous further development, the guide bar is arrangedon or fastened to the soil compacting machine in a vibration-dampened orvibration-insulated manner. Preferably, the guide bar is furtherarranged on a frame of the superstructure of the soil compacting machinewhich also accommodates the internal combustion engine. The term “frame”shall be interpreted in a broad fashion and shall also comprise aself-supporting construction of the internal combustion engine.

At least one elastic damping element may be present for vibrationinsulation or damping of the guide bar, which damping element alsoallows the conduction of the combustion air. The damping element thusassumes a multiple function in this embodiment of the invention(conduction of the combustion air and vibration damping).

The damping element may be arranged as a rubber buffer with at least onebore hole, preferably an axial bore hole, for conducting the combustionair. The combustion air can be conducted through this bore hole. In thiscase, the integrated flow channel thus opens at least on one side intothe rubber buffer. A rubber buffer is characterized by itsrubber-elastic properties. Preferably, a rubber buffer is made of anatural material or an artificial material. This also includes elasticsilicone materials.

It is provided according to a preferred further development that theflow connection between the integrated flow channel and the bore hole inthe rubber buffer is realized by means of a connecting flange. Thisconnecting flange may be arranged as a separate component which can bearranged in an L-shaped or T-shaped manner. In particular, thiscomponent can also be identical to the one for flow connection betweenthe air-filter unit and the integrated flow channel.

A fuel tank may also be further arranged on the guide bar. This offersthe advantage for example of a similarly vibration-dampened suspensionof the fuel tank. One fundamental idea of this further development isalso to provide several additional functions to the guide bar inaddition to the further conducting of combustion air.

It is also provided that the air-filter unit and the fuel tank arearranged in a common housing. This will be explained be-low in closerdetail in connection with the drawings. The term “housing” alsocomprises holding apparatuses and the like which are capable offastening the fuel tank and the air-filter unit to the guide bar. Thisallows for further reduction in overall space in an outstanding way anda further reduction of individual parts. This arrangement of anair-filter unit and a fuel tank in a common housing on an initiallymentioned soil compacting machine and especially on its guide bar canalso occur independently from a guide bar with a flow channel.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained below in closer detail by reference tothe drawings, with the same reference numerals indicating the samecomponents, with the drawings showing schematically:

FIG. 1 shows a soil compacting machine according to the state of the artin a perspective view;

FIG. 2 shows the superstructure of a soil compacting machine accordingto an embodiment of the present the invention in a perspective view; and

FIG. 3 shows a top view of the soil compacting machine of FIG. 2 in apartial sectional view.

DETAILED DESCRIPTION

In accordance with FIG. 1, a generic soil compacting machine which isknown from the state of the art and is arranged as a vibration tamper 10comprises a substructure 20 and a superstructure 30. The substructure 20comprises a compacting plate or tamping plate 21 and the superstructure30 an internal combustion engine 31 with an air-filter unit 32, a fueltank 33 and a guide bar 34. The internal combustion engine 31 drives thecompacting plate 21 in a manner known from the state of the art via acrank mechanism (not shown) which is arranged partly behind the coverplate 50.

Aspects that are relevant to the invention will be explained below byreference to FIGS. 2 and 3.

FIG. 2 shows, among other things, the superstructure 30 of the vibrationtamper 10. The superstructure 30 comprises an internal combustion engine31 and guide bar 34′ in accordance with the invention. The guide bar 34′offers various handling features for a user in order to enable keepingthe vibration tamper 10 in operation or to guide the same. The guide bar34′ is arranged in a vibration-dampened or vibration-insulated manner attwo fastening points via the damping elements 35 a and 35 b on a frameof the superstructure 30. It is understood that also any other number offastening points could be provided. The damping elements 35 a and 35 bare arranged as integral rubber buffers. It is understood that also amulti-part arrangement of these damping elements 35 a and 35 b would bepossible.

An air-filter unit 32 and a fuel tank 33 are fastened in a commonhousing 40 to the guide bar 34′. As a result of this special manner ofarrangement on the guide bar 34′, the air-filter unit 32 and the fueltank 33 are thus also arranged in a vibration-dampened orvibration-insulated manner on the vibration tamper 10. A common housing40 further allows simple and rapid mounting or dismounting of thesecomponents and further leads to a reduction in weight. The cover overthe air-filter unit 32 has been removed for the purpose of betterillustration. In the separating area between the air-filter unit 32 andthe fuel tank 33, the common housing 40 is arranged with a double wallwith an air gap. When seen from the internal combustion engine 31, theair-filter unit is arranged substantially before the fuel tank 33 in thecommon housing 40. It is alternatively possible to arrange theair-filter unit 32 also behind the fuel tank 33. It is understood thatthe air-filter unit 32 and the fuel tank 33 can also be arranged asseparate components on the guide bar 34′, i.e. without any commonhousing 40.

The combustion air required for the combustion process in the internalcombustion engine 31 is supplied, and especially drawn in, via theair-filter unit 32. It is now provided in accordance with the inventionthat this supplied combustion air flows from the air-filter unit 32 tothe internal combustion engine 31 via a section of the guide bar 34′which is designated with 34A. The direction of through-flow is indicatedwith the arrow shown in FIG. 2. This section 34A of the guide bar 34′thus comprises an integrated flow channel.

For this purpose, at least this section 34A of the guide bar 34′ isarranged as a hollow section, with the cavity representing theintegrated flow channel. In the illustrated embodiment, the hollowsection is realized by a tube with a circular cross section, with othershapes of cross sections being possible. The integrated flow channelextends in the present case from a fastening point of the air-filterunit 32 up to a fastening point of the guide bar 34′ on the frame of thesuperstructure 30. In the region of the section 34A, the flow channelhas a straight axial expansion. The flow channel 34A can also have anydesired curved axial extension, irrespective of the respectivearrangement of the guide bar 34′.

The combustion air is introduced into the integrated flow channel at thefastening point of the air-filter unit 32 at the guide bar 34′ andguided out of the same at the fastening point of the guide bar 34′ onthe frame of the superstructure 30. As an alternative to this or inaddition, the combustion air can principally flow on other flow pathsthrough the guide bar 34′, with short and substantially straight flowpaths being preferable.

The introduction of the combustion air into the integrated flow channeloccurs by means of a separate connecting flange 37. The connectingflange 37 is thus arranged in such a way that a flow connection (i.e. aconnection through which the combustion air can flow from the air-filterunit 32 into the integrated flow channel) is produced between the flowchannel integrated in the guide bar 34′ or 34A and the air-filter unit32. This connecting flange 37 can also be designated as a connectingflange 37 on the air-filter side.

The discharge of the combustion air from the integrated flow channeloccurs through the damping element 35 a. It is provided for this purposein accordance with FIG. 3 with an axial, circular-cylindrical andcentral bore hole 36 a. The discharge through the damping element 35 aoccurs via a connecting flange 38 which connects at least the section34A of the guide bar 34′ with the damping element 35 a in the mannerthat a respective flow connection is obtained. This connecting flange 38can also be designated as the connecting flange 38 on the motor side.The flow through section 34A of the guide bar 34′ and the dischargethrough the axial bore hole 36 a in the damping element 35 a is shownschematically in FIG. 3 with the flow arrows.

The section 34A of the guide bar 34′ which is disposed between theconnecting flanges 37 and 38 can preferably have a larger diameter, andespecially a larger inside diameter, than the other sections of guidebar 34′. The section 34A is especially arranged as a separate straightpipe section. It can also be provided to arrange only this section 34Aas a hollow section.

The combustion air is guided from the damping element 35 a to theinternal combustion engine 31 by means of a separate flow connection ora flexible air hose 39. It is alternatively possible to forward theflowing air through an integrated flow channel within the frame ofsuperstructure 30. The damping element 35 a is used both for damping orinsulating vibrations of the guide bar 34′ and the conduction ortransmission of the combustion air. Moreover, the damping element 35 aprovides sealing in the connecting area and prevents the intake ofsecondary air. The damping element 35 a thus assumes a multiplefunction.

The flow channel integrated in the guide bar 34′ or 34A advantageouslyenables a reduction in weight or mass, especially in the superstructure30 of the vibration tamper 10. It is thus possible to omit the entireair-filter housing as shown in FIG. 1 for example. This leads to areduction in overall space and individual parts. Moreover, performedmeasurements having not shown any reduction in the engine output.

The many features and advantages of the invention are apparent from thedetailed specification, and, thus, it is intended by the appended claimsto cover all such features and advantages of the invention which fallwithin the true spirit and scope of the invention. Further, sincenumerous modifications and variations will readily occur to thoseskilled in the art, it is not desired to limit the invention to theexact construction and operation illustrated and described, and,accordingly, all suitable modifications and equivalents may be resortedto that fall within the scope of the invention.

1. A hand-guided soil compacting machine, comprising: an internalcombustion engine for driving a compacting plate; and at least one guidebar, for holding and/or guiding the soil compacting machine, includingat least one flow channel through which a supply of combustion air tothe internal combustion engine flows at least in sections.
 2. A soilcompacting machine according to claim 1, wherein the flow channel isintegrated in the guide bar.
 3. A soil compacting machine according toclaim 2, wherein the guide bar is formed at least in sections from ahollow section whose cavity forms the integrated flow channel.
 4. A soilcompacting machine according to claim 2, wherein at least one air-filterunit is arranged on the guide bar which is in fluid connection with theintegrated flow channel.
 5. A soil compacting machine according to claim4, wherein the fluid connection between the integrated flow channel andthe air-filter unit is realized by means of a connecting flange.
 6. Asoil compacting machine according to claim 1, wherein the guide bar isfastened in a vibration-dampened manner to the soil compacting machine.7. A soil compacting machine according to claim 6, wherein thevibration-dampened fastening of the guide bar comprises at least oneelastic damping element which allows conducting the combustion air.
 8. Asoil compacting machine according to claim 7, wherein the dampingelement is arranged as a rubber buffer with at least one bore hole forconducting the combustion air.
 9. A soil compacting machine according toclaim 8, wherein the bore is an axial bore hole.
 10. A soil compactingmachine according to claim 8, wherein the fluid connection between theintegrated flow channel and the bore hole in the rubber buffer isrealized by means of a connecting flange.
 11. A soil compacting machineaccording to claim 1, wherein a fuel tank is arranged on the guide bar.12. A soil compacting machine according to claim 11, wherein theair-filter unit and the fuel tank are arranged in a common housing.